1. Field of the Invention
The present invention generally relates to a flowmeter for measuring the flow rate of a liquid, or a liquid with suspended solids, through a pipe system without physical contact between the liquid and the measuring elements of the flowmeter.
2. Related Art
There are numerous types of flowmeters for measuring the flow rate of liquid, but no suitable instrument exists for measuring the flow rate of liquid-solid suspensions or measuring the flow rate of corrosive liquids, or liquids with corrosive solids. Prior flowmeters are not suitable for such applications because the flowmeters, or portions thereof, generally make contact with the liquid, and where liquid-solid suspensions exist, or the liquid or solid is corrosive, interference is created with any internal propellers, rotors or tubing that may comprise such flowmeters. As such, when used in connection with liquid-solid suspensions, or corrosive liquids or corrosive suspended solids in the liquid, existing flowmeters accumulate solids, are corroded, or both, causing them to lose calibration, and ultimately become completely inoperable.
What is desired, but has not heretofore been developed, is a flowmeter that is capable of measuring the flow rates of liquids, which may include particulate suspended solids, and wherein the liquids or solids, or both, may be corrosive. The flowmeter of the present invention accomplishes these objectives because there is no contact between the measuring elements of the flowmeter and the liquid whose flow rate is being measured.
The present invention provides a flowmeter for measuring the flow rate of liquids or liquid-solid suspensions within a pipeline, without physical contact between the liquid or liquid-solid suspension and the measuring elements of the flowmeter. The measuring elements of the flowmeter are isolated from the liquid or liquid-solid suspension. The flowmeter can be used for measuring the flow rate of a liquid or liquid-solid suspensions wherein the liquid and/or suspended solid is corrosive. The flowmeter includes flexible couplings and a strain gauge or strain gauge assembly.
The present invention relates to a flowmeter for measuring the flow rate of liquids, or liquid-solid suspensions in which liquids and/or suspended solids may be corrosive. The flow rate is measured without any physical contact between the measuring components of the flowmeter and the liquid or liquid-solid suspension. The flowmeter is connected between upstream and downstream piping. A first flexible coupling is connected to the upstream piping and is preferably the same diameter as the upstream piping. A reducing coupling and a second flexible coupling of smaller diameter is connected downstream of the first flexible coupling. Extending from the second flexible coupling is a reverse reducing coupling, followed by the downstream piping of the same diameter as the upstream piping. One or more strain gauges are interconnected with the second flexible coupling. The one or more strain gauges can be attached to one or more rigid strips which can be attached in the direction of flow to the upstream and downstream flanges of the second flexible coupling. The force of flow on the first reducing coupling creates a higher velocity flow in the outlet of the first reducing coupling and within the second flexible coupling. The resulting upstream momentum force tends to urge the first reducing coupling, and the second flexible coupling connected thereto, towards the upstream piping. Such movement is translated to the rigid strips or bolts connected across the second flexible coupling and the resulting force is measured by the one or more strain gauges attached to the rigid strips or bolts. The second reducing coupling is reversed so that its larger diameter faces downstream and is preferably the same diameter as the upstream piping. The flowing liquid or liquid-solid suspension thus expands to fill the downstream piping at the same average velocity as that in the upstream piping.
In one embodiment of the present invention, a strain gauge assembly is connected to flanges of the second flexible coupling. The strain gauge is tensional by movement of the second flexible coupling caused by fluid flow. The strain gauge can be supported by a plate with support legs to prevent vertical movement of same. The support legs and plate are adjustable, allowing the strain gauge assembly to be supported at desired heights. The flexible couplings can also be supported.